Pandora's Makeup Box's Eyeshadow Primer is honestly the best primer that I have. A little of the product goes a LONG way, so this product will definitely last you a long time! It goes on a nude colour, and allows eyeshadow to be true to colour and long lasting.
I put my eyeshadow on at 7am, and by 9pm it still looked great! No smudges, discolouring, fading, etc. :)